This invention relates to the field of fluid-material assays, and especially to a significantly improved assay-response, thin-film-based pixel matrix which offers a very high degree of controlled, assay-response, pixel-specific sensitivity with respect to which an assay response (a) can be output-read on a precision, pixel-by-pixel basis, and (b) can additionally be examined along uniquely accessible, special, plural and freely selectable, independent-variable “information-gathering axes”, such as a time-sampling axis, and an electromagnetic-field-variable (light, heat, non-uniform electrical) axis.
Preferably, and in the above context, the invention takes the form of a relatively inexpensive, consumer-level-affordable, thin-film-based assay structure which features a low-cost substrate that will readily accommodate low-cost, and preferably “low-temperature-condition”, fabrication thereon of substrate-supported matrix-pixel “components”. “Low temperature” is defined herein as a being a characteristic of processing that can be done on substrate material having a transition temperature (Tg) which is less than about 850° C., i.e., less than a temperature which, if maintained during sustained material processing, would cause the subject material to lose dimensional stability. Accordingly, while the matrix-pixel technology of this invention, if so desired, can be implemented on more costly supporting silicon substrates, the preferred supporting substrate material is one made of lower-expense glass or plastic materials. The terms “glass” and “plastic” employed herein to describe a preferred substrate material should be understood to be referring also to other suitable “low-temperature materials. Such substrate materials, while importantly contributing on one level to relatively low, overall, end-product cost, also allow specially for the compatible employment, with respect to the fabrication of supported pixel structure, of low-temperature processes and methods that are based on amorphous, micro-crystal and polysilicon thin-film-transistor (TFT) technology. In particular, these substrate materials uniquely accommodate the use of the just-mentioned low-temperature TFT technology in such a way that electrical, mechanical and electromagnetic field-creating devices—devices that are included variously in the structure of the invention—can be fabricated simultaneously in a process flow which is consistent with the temperature tolerance of such substrate materials.
Regarding the preference herein for the use of low-temperature TFT technology, and briefly describing aspects of that technology, low-temperature TFT devices are formed through deposition processes that deposit silicon-based (or other-material-based, as mentioned below herein, and as referred to at certain points within this text with the expression “etc.”) thin film semiconductor material (which, for certain applications, may, of course, later be laser crystallized). This is quite different from classic silicon CMOS device technology that utilizes a single-crystal silicon wafer bulk material as its semiconductor material. While the resulting TFT devices may not have the switching speed and drive capability of transistors formed on single-crystal substrates, TFT transistors can be fabricated cheaply with a relatively few number of process steps. Further, thin-film deposition processes permit low-temperature TFT devices to be formed on alternate substrate materials, such as transparent glass substrates, for use, as an example, in liquid crystal displays. In this context, it will be understood that low-temperature TFT device fabrication may variously involve the use typically of amorphous Si (a-Si), of micro-crystalline Si, and or of polycrystalline Si formed by low-temperature internal crystalline-structure processing of amorphous Si. Such processing is described in U.S. Pat. No. 7,125,451 B2, the contents of which patent are hereby incorporated herein by reference.
For the sake simply of convenience of expression regarding the present invention, and in order to emphasize the “low-temperature” formation possibility which is associated with the invention in its preferred form, all aspects of assay-matrix pixel fabrication and resulting structure are referred to herein in the context and language of “low-temperature silicon on glass or plastic” construction, and also in the context and language of “low-temperature TFT and Si technology”.
Returning now to a more detailed, preliminary view of the invention, it pertains to a novel fluid-material assay matrix structure, also referred to herein as a microstructure, which takes the form of a pixelated, active-matrix, row-and-column, fluid-assay, micro-structure characterized by a selected grouping of individually electronically-digitally-addressable pixels, which pixel, and their contents, are formed preferably on a glass or plastic substrate utilizing the above-mentioned low-temperature TFT and Si technology. The concepts of digital addressability and energizing expressed herein are intended to refer to computer-controlled addressability and energizing. The pixels in this selected grouping, which may include either an entire matrix of pixels, or one of a number of possible lower-pixel-count submatrices (later to be described herein) within an overall matrix, have been appropriately prepared on a supporting substrate, with each pixel therein possessing, in addition to appropriate, relevant, computer-accessible electronic switching structure, an included assay sensor which hosts an assay site that has been affinity-functionalized to assist in the performance of a particular kind of fluid-material-specific assay.
With respect to the concept of assay-site functionalization, except for the special features enabled by practice of the present invention that relate (a) to “pixel-specific” functionalization capability, and (b) functionalization under the “control” of a “digitally energized and character-managed”, “assay-site-bathing” ambient electromagnetic field of a selected nature, assay-site functionalization is in all other respects essentially conventional in practice. Such functionalization is, therefore, insofar as its conventional aspects are concerned, well known to those generally skilled in the relevant art, and not elaborated herein, but for a brief mention later herein noting the probable collaborative use, in many functionalization procedures, of conventional flow-cell assay-sensor-functional processes.
While ultimately-enabled functionalization specificity for a particular selected assay site (resident within a given pixel), in accordance with practice of the present invention in certain instances, is generally and largely controlled by ambient “bathing” of that site with selected-nature electromagnetic-field energy received from an invention-prepared, digitally-energized, appropriately positionally located electromagnetic field-creating subcomponent, it turns out that site-precision specificity is not a critical operational factor. In other words, it is entirely appropriate if the entirety of a pixel becomes ultimately “functionalized”. Accordingly, terminology referring to pixel functionalization and to assay-site functionalization is used herein interchangeably.
Each pixel, which is an active-matrix pixel as that language is employed herein, also includes, as was mentioned, a special, pixel-specific, digitally and controllably energizable and employable, assay-site-bathing (also referred to as “pixel-bathing”) electromagnetic field-creating structure which may be used, selectively and optionally, as a special assistant in the above-mentioned, “special-information-axis” reading-out of assay results, to generate a selected type of environmentally-pixel-bathing electromagnetic field, such as a light field, a heat field, and a non-uniform electrical field. Of course, pixel-by-pixel assay-result output reading may also be accomplished in appropriate circumstances without any use of the field-creating structure.
This interesting and unique field-creating feature of the invention, coupled with the invention's enablement of pixel-by-pixel, assay-result output reading, are what introduce and promote, among other things, the possibility of deriving assay-result data, including time-based and kinetic assay-reaction data, effectively along the above-suggested, special information axes not enabled by prior art devices. For example, and with respect to the performance, or performances, of a selected, particular type of fluid-material assay, pixels in an appropriately functionalized group of pixels may have been, before matrix delivery to a user, initially functionalized utilizing plural different intensities of functionalization-assist electromagnetic fields, such as intensity-differentiated heat and/or non-uniform electrical fields. Such differentiated field-intensity functionalization which becomes reflected in a final matrix, and which was performed by pixel-on-board electromagnetic field-creating structures, can, in an assay output-reading situation, yield information regarding how an assay's results are affected by “field-differentiated” prepared-pixel functionalization, also referred to herein as assay-site functionalization. Similarly, assay results may be observed by reading pixel output responses successively under different ambient field conditions that are then “presented” seriatim as spatial bathing fields to information-outputting pixels. Further, time-axis output data may easily be gathered on a pixel-by-pixel basis via pixel-specific, digital output sampling.
The invention thus takes the form of an extremely versatile and relatively low-cost fluid-material assay structure, which, because of its pixel-by-pixel functionalization characteristic, may be constructed, and delivered to an assay-performing user (as will be seen from discussion text presented hereinbelow) in a variety of different pre-assay conditions. A finished, user-delivered matrix structure constructed in accordance with the present invention may be delivered with all of its pixels functionalized to handle a single, specific assay. Alternatively, such a matrix structure may be delivered to a user with different pixels functionalized differently (i.e., submatrix functionalization) so as to enable a single matrix to be employed in the conducting of plural, different assays. More will be said about this “submatrix” feature of the invention later herein.
Regarding the making of a matrix micro-structure as proposed by the present invention, an important point to note is that the processes, procedures and methodologies which are employed specifically to fabricate this structure may be drawn entirely from conventional micro-array fabrication practices, such as the earlier-mentioned TFT, Si, low-temperature, and low-cost-substrate technology practices, well known to those generally skilled the art. Accordingly, the details of these practices, which form no part of the present invention, are not set forth herein. Those generally skilled in the relevant art will understand, from a reading of the present specification text, taken along with the accompanying drawing figures, exactly how to practice the present invention, i.e., will be fully enabled by the disclosure material in this application to practice the invention in all of its unique facets.
With the above having thus been said about the general nature of the present invention, the various features and advantages thereof, including those generally set forth above, will become more fully apparent as the detailed description of the invention which follows below is read in conjunction with the accompanying drawings.